Refrigerating machine



J. E. MITCHELL ET AL REFRIGERATING MACHINE Filed Jan. 6, 1922 'fII:IIZII 44 FLOATVALVE y Patented Dec. 2 1924.

UNITED STATES PATENT OFFICE.

JOHN E. MITCHELL AND WALTER G. E. ROLAFF, OF ST. LOUIS, MISSOURI, ASSIGNORS TO,

WALTER G. *E. BOLAFF, 0']? ST. LOUIS, MISSOURI.

nnrnrennarriw MACHINE.

Application filed January 6, 1922. Serial No. 527,301.

To all whom it may concern:

Be it known that we, JOHN E. MITCHELL and WALTER G. E. ROLAFF, citizensof the United States, residing in the city of St. Louis and State ofMissouri, have invented new and useful Improvements in RefrigeratingMachines, of which the following is a specification.

This invention relates to refrigerating machines and has for one of itsobjects to provide a machine of this character in which the lubricationof the working parts is automatically efiected in the operation of themachine, and at the same time, the body of lubricant employed operatesto prevent any leakage of gas from the machine.

Other objects of the invention relate to the provision of arefrigerating machine in which the high pressure or condensing chamberis superimposed upon the low pressure or evaporating chamber, thecompressors being located in the low pressure chamber and operated by ashaft passing from the outside through the low pressure chamber andhaving hearings in corresponding walls of the two chambers; to provlde areciprocating refrigerating machine which shall be dynamically andmechanically bal-' anced; to provide a reciprocating refriger atingmachine in which the cylinders of the -compressors are insertable fromthe outside into the low pressure chamber and are substantially entirelysurrounded by the cool gas of said chamber; to provide automaticlubricating means involvin the maintenance of a substantiallyuniformieight of a lubricant in the high pressure and low pressurechambers, the provision of means for controllably discharging lubricant"from the high pressure chamber by the pressure of gas therein, itsautomatic application to the moving parts of the machlne and passage tothe low pressure chamber, and the continuous return of the lubricant tothe high pressure chamber effected by the operation of the compressm'slocated in the low pressure chamber; to provide a novel construction ofrefrigerating machine of the reciproeating type in which a verticallydisposed drive shaft enters the machine through a stufiing box in thebottom of the low pressure chamber and in which chamber a body oflubricant is constantly maintained and hasv free access to said stuffingbox whereby the latter is sealed against the escape of gas".

' The above objects of the invention are atto be characterized by thefollowing salient features:

A high pressure chamber superimposed upon the low pressure chamber; avertically disposed shaft driven at its lower end by a motor, enteringthe machine through a stufling box in the bottom of the low pressurechamber and passing into the high pressure chamber, the port through thestufiing box constituting the only opening containing a moving partthrough which gas might escape and which opening is sealed against suchescape of gas by means of a body of lubricant maintained in the bottomof the low pressure chamber and having free access to said stufling box;a body of lubricant maintained in the high pressure chamber;

a means of communication between the high pressure chamber and thecompressing mechanism in the low pressure chamber; a. valve member onthe upper end of the, vertical shaft operating alternately to open andclose said communication whereby the pressure of gas in the highpressure chamber will cause a certain amount of the lubricant to beforced through the means of communication to the low pressure chamber tofallupon said moving parts which act as distributing agents to conveythe lubricant to all parts of the machine, after which the lubricantflows to the bottom of the low pressure chamber; a plurality ofcompressors, preferably two, located oposite each other in the lowpressure cham r with means for operating the pistons thereofsynchronously in the same operative direction to effect simultaneoussimilar actions by each piston; and means for insuring a uniform andequal return of-the lubricant from the low pressure chamber to the highpressure chamber by each of the compressors.

In the drawingi Figure 1 represents a vertical sectional vieaw of amachine embodying our,invention;

Figure 2 is a detached sectional view on the line 22 of Figure 1.

Referring now to the drawing, the numeral 1 indicates a support for themachine, which is in the form of a cylindrical casing surrounding amotor 2. As shown, the

cylindrical .support- 1 is provided with an interior annular flange 3and "the motor 1s provided with a correspondin v. outwardly projectingannular flange 4 whic rests upon the flange 3 to which it is secured bymeans the lower edge of the wall, as shown. The

chamber 9 is provided with a removable bottom 10 which has shoulderedconnection with an annular flange 11 projectin inward from the wall 8and is bolted in flui and gas tight relation to said flange by means ofthe bolts 12. The bottom 10 is provided on its upper side with a bearing13 for the shaft 6 and on its under side supports a stuffing box 14 ofconventional construction, through which said shaft extends. The bearing13 is provided with a series of apertures 15 for permitting lubricant a1supplied to the chamher 9, to pass directly to the packing 16 of thestalling box for the purpose of sealing the opening surrounding theshaft against escape of gas from the chamber 9. This chamber constitutesthe low pressure chamber of the machine and, as stated above, it ischaracteristic of the invention that the compressors of the machine arelocated in this chamber, and this construction and arrangement will nowbe described.

The wall 8 is provided at a plurality of points, preferably two locateddirectly opposite each other, with circularo enin'gs" 171 through whichare inserted from t e outside, the c linders 18 of two compressors,these 0 lin ers being of less diameter than that of t e opening 1 toprovide a space the thickness of the wall 8 at this point surroundingthe cylinders; Each of the cylinders is provided with ports 19communicating with the space referred to and, therefore with theinterior of the chamber 9. Each of the cylinders is provided on itsouter end with a head 20 and each of these heads is provided with anannular flange 21 which has shouldered connection with the wall 8surrounding the aperture 17 and is secured thereto in fluid and gastightrelation by bolts 22. Each of the heads 2Ov also provides a valvechamber 23 which is closed on the outer side by a plate 24. A; cap 25 isscrewed onthe outer end of each of the heads 20 and securely closes theend of the head 20 and seals it against the escape of any gas. which mayass by the plate 24. Projecting inwardly rom the plate 24 is a lug 26,this in and the plate 24 with which it is integrah ing Each of theapertured to slidably'receive a stem 27 projectinginwardly from acircular plate 28 which is in'the nature of a floating head and actsas'a valve to control the openin of the inner end of the cylinder 18. Acoi spring 29 extending between the plates 24 and floating heads 28operates to-holdthe latter in yielding contact with the inner end of thecylinder 18. Mounted in each 0 linder 18 is a piston 30 which in itsoutwar throw, as shown in the drawing, reaches a point sub-v stantiallyflush with theouter end of the cylinder. Mounted in each of the pistons30vis a wrist pin 31 with which is pivotally connected the outer end ofa piston rod 32. istons 32 is provided on its outer end wit a ring 34%which surrounds and is supported on a cam disk 35 mounted on the shaft6. The respective cam disks 35 are mounted in superposed relation andoppositely disposed so that the pistons 30 move in unison inwardly andoutwardly. By this arrangement the dynamic and mechanical forces areequalized or balanced and a smooth running machine is insured. in orderto assist in carrying the pistons through the compression zones, weprefer to utilize the inertia of the fly-wheel 7 to further insure thesmooth and even running of the .machine. To insure the adequate oilingof the cam disks and rings. the following constructlon and arrangement15 'providedr.

The upper eccentric ring 35 has mounted on its upper side an invertedconical cup 36,

*open at its upper end and surrounding the shaft 6, which receiveslubricant supplied from the high pressure chamber in a manner to helater described.- The upper cam disk 35 is provided with a duct 37leading from the outer surface of the disk on the inside of the cup 36to the periphery of the disk. This upperdisk is also provided with avertically dis osed duct 38 the upper end of which is wit in the cup 36and the lower end of which communicates with a duct 39 in the .lowerdisk35 whichlatter duct extends through to the periphery of its disk. It maybe briefly noted at this point that lubricantfrom the cup 36 will passthrough the ducts 37, 38 and 39 and will be thereby supplied tolubricate the bearings of the cam disks 35 and rings 34.

As previously mentioned, a characteristic of the invention is the factthat the high pressure or condensing chamber. is superimposed upon thelow pressure chamber. This arrangement and the construction andoperation of artsi'issociated therewith will now be descri d. e W a Thehigh pressure chamber 40 is formed by a hollow circular head 41 and acircular Wall 42 projecting upward from a circular web or partition -13which is at once the top of the chamber 9 and the bottom of the chamber40. The lower edge of the wall ill) tion by means of a plurality ofbolts 45,

the connection, of course, being fluid and gas-tight. Each of the valvechambers 23 previously referred to, is provided at its bottom with aport 46 from each of which a pipe v4'2 leads to and communicates withthe high pressure chamber 40. Located within the high pressure chamber40 is acondensing coil 48 which has inlet and outlet pipes 49 and 50respectively, communieating with a suitable source of cold watercirculation. The numeral 51 indicates the outlet pipe for conducting theliquid refrigerant from the chamber 40 which pipe is provided on theinterior of the chamber with a goose-neck 52, the mouth'o'f which isadapted to be submerged in the liquid re frigerant as the latter risesin the chamber so that the refrigerant may escape under the pressure inthe. chamber through this pipe. After passing through the room,container, or other zone of refrigeration, the refrigerant in the formof a gas is conducted into the low' pressure chamber 9 through a pipe51*, which, of course, is a continuation of the pipe 51 and which entersthe chamber 9 through the bottom 10 thereof. Within the chamber 9 theoutlet end of the pipe 51", indicated by 52, is located above thesurface of the body of lubrilcJant w always maintained in said cham-'Referring again to the chamber 40 the heavy hatched lines 02' indicatea body of lubricant while the lighter hatched lines y indicate theliquid refrigerant which rests upon the body of the lubricant. Themanherof circulating the lubricant will now be described.

Centrally of the partition 43 there-is provided a bearing 53 for theshaft- 6 and through which said shaft extends into the chamber 40. Onits upper end within this chamber the shaft has secured, as by beingscrewed thereon as shown, a'circular valve 54 the seat for which isafforded by the upper side of the bearing 53, which for this purpose isprovided with a circular projection 55, at least the lower side of whichisalways submerged in the body of lubricant m. At a given point near itsouter edge the circular projection 55 is provided with a verticallydisposed aperture 56. The bearing 53 isprovided with a parallel aperture01' duct 57 which extends from the top of the bearing through the sameand communi- (ates at the lower end of the bearing withthe chamber 9immediately over the open end of the cup 36. The valve 54 normallycloses the aperture 56 but it is provided on its under side with acut-away portion or recess 58, which when it passes over the top of theaperture 56, which-position is shown in the drawing, establishescommunication through the ports 56 and'57 between the high pressurechamber 40 and the low pressure chamber 9, so that the pressure of gasin the former chamber bearing upon the lubricant, will force the same upthrough the port 56, whence it passes through the recess 58 underthevalve andri-nto the duct 57, dropping into the cup 36. yThis actionoccurs in each complete revolution of. the valve 54. It should be statedthat the. valve 54 is in the form. of a ring valve which -af fordsbetween itsainner circumference and the disk, a chamber GOinto which thelubricant passes from therecess the valve before escaping through athe"duct 57 into the cup 36. The circular projection 55 of the bearing isreduced and screwthreaded in its upper portion toreceive a screw 'cap 61which 'at once shieldsthe valve 54 and bearing 53 against access of the"liquid refrigerant in the chamber 40 -z iiid also forms on top of thebearing a chamber to retain the lubricant forced through the aperture 56in the manner previously described. The manner of returning thelubricant from the low pressure to the high pressure chamber is asfollowsz 'f" The numerals 62 indicate two pipes-now municating with thecylinders "18 slightly in advance ofthe ports lti therein and leadingtherefrom toa point adjacent the hearing 13 where they are connected by;coupling 63, the leg;of .,the coupling having its open end locatednearthe surface of the body of lubricant fw in the low'p'ressurechamber,-forming' as' it were, an inverted cup. With each inward strokeof c the pistons lubricant will be drawn by suction into the T-coupling63 andthence through the pipes 62 intoeach cylinder, and with eachoutward stroke, it'will be forced,

along with the refrigerant, through ports 21:2 and pipes 47 into thehighpressure cham- In operation a container of a liquid refrigerant,peferably methyl chloride, is connected in any suitable way to .thelowpressure side of the system and the imotor 2 placed in operation and oneach inward stroke of the pistons 30, the aseous methyl chloride will bedrawn. into t e' fcylinders 18 through theports 19 and 'on-each outwardstroke of the pistons the gas will be com-- converted into a liquidform. A float valve cant :0 previously supplied to this chamber.

A body of liquid refrigerant, indicated by y in the drawing, will thusbe constantly formed and maintained in the chamber 4( and which willrest upon the body of lubri- The liquid refrigerant will escape throughthe goose neck 52 and pass by way of the pipe 51 through the refricrating system and thence return as a gas is rough the plpe 51 to bedischarged through the outlet 52 of said pipe into the low pressurechamber 9 whence it will enter the compressors and be returned to thehigh pressure chamber, as previously described. With each completerevolution of the shaft 6 the recess 58 in the valve 54 will be causedto pass over the aperture 56 in the circular projection and lubricantwill thus be forced by the pressure in the chamber 40 through saidaperture into the chamber 60 and passin down through the duct 57 bedischarged into the cup 36, being thrown outward against the wall ofsaid cup by centrifugal force. From this cup it asses through the ducts37, 38 and 39 to ubricate the eccentrics on the shaft, as previouslydescribed. This lubricant then falls into the bottom of the low pressurechamber and maintains a substantially uniform height of lubricanttherein, as indicated by m The lubricant thus deposited in the lowpressure chamber is returned to. the high pressure chamber by the actionof the com ressors in the manner reviously describe One of the principalfeatures of the invention is the fact that the body of liquid in the lowressure chamber 9 is always accessible under the force of gravity andthe slight pressure in the chamher 9, to the stufling box 14,.by meansof the apertures 15 in the bearing 13; so that it is impossible for gasin the chamber 9 to escape through the stuifing box 14. Of course, thepacking 16 of the stufiing box can be compressed as tightly about theshaft as may be desired by screwing up the cap of the box in the usualway.

Referring to the low pressure chamber 9, it will be seen that thecylinders 18 are in-.

serted from the outside into said chamber and project well toward thecenter thereof and are surrounded throughout practically their entirelength by the cool gas in said chamber which thus tends to prevent theheat of com ression from causing a too rapid expansion of the gas thatis drawn into the c linders'. This, as is well understood, wil increasethe efliciency of the apparatus.

It will furtherfbe seen that the outside invention contemplates.

ends of the cylinders or cylinder castings which have been referred toas heads, are closed by removable heads or covers 25, and as thecylinders themselves are removable the ready assemblage of the parts andequally ready access to all parts of the movable mechanism' in orconnected with the low pressure chamber is assured.

We should point out that in the reciprocation of the pistons of thecompressors not only is the lubricant returned to the high pressurechamber, but in this 0 eration it is also necessarily supplied to andistributed over the interior of the cylinders so as to thoroughlylubricate the pistons and cylinders and the connections of the pistonrods with thepistons. The thorough lubrication of all movable partsprovided for by our invention is of great importance in high speedreciprocating machines such as our Not onl is the thorough lubricationof the cylin ers provided for as described, but as the lubricant in thelow pressure chamber is always in contact with the cold gaseousrefrigerant, the lubricant is maintained at a relatively low temperatureand is an important factor in cooling the cylinders.

Another feature of. great importance and, in fact, necessary to thesuccessful operation of a refrigerating machine of the reciprocatingtype shown, at a very hi h rate of speed, is the provision of thefloating heads at the ends of the cylinders in combination with theinlet ports 19 for the gaseous refrigerant. In other words, theconstruction is valveless, so to speak, for, while the floating headsact in the nature of valves, they differ from an ordinary valve in thearea uncovered relative to the area of compression released. In otherwords, on the out stroke of the piston when the gas has been compressedto a certain point, the whole end of the cylinder is uncovered and aninstant release of the pressure in the cylinder over its entire area iseffected. There is no danger, therefore, of building up pressure in thecylinder by rapid successive compressions of the gas due to aninadequate area of expulsion of the gas which would almost certainlresult from the use of ordinary valves ailording only a relatively smallarea of expulsion for the gas. These floating heads are equallyimportant in connection with the lubricating feature described forrelatively large quantities of the lubricant will be drawn into thecylinders on each suction stroke, it is of the utmost importance thatthe free discharge of this lubricant should occur at each compressionstroke of the pistons, and this is provided for by the floating headswhich, as will be a parent, yield under compression to permit ubricantto be discharged 5mm the entire inner surface of each cylin- Again, asthe pistons move inward and uncover the inlet ports, the gas can rapidlyenter the cylinder, as the ports are not controlled by valves. 'Therapid entrance of the gas is facilitated by the relatively large area ofinlet afforded by the openings around the-cylinder, by the partialvacuum produced on the interior of the cylinder by the movement of thepiston and by the pressure in the low pressure chamber which, while notconsiderable, say about 7 lbs. to the square inch, is sufficient underthe conditions named to effect a rapid entrance'o the gas into thecylinder.

In practice the pistons reciprocate at from 1000 to 1200 times perminute. NotwIthstanding, due to the dynamic and mechanical balance whichthe construction provides, the thorough automatic lubrication of allparts-sub ect to movement and friction, and the provision for the rapidingress. of the gas into and its ready and complete expulsion from thecylinders, we have demonstrated in practice. that a inachine soconstructed and having the characteristics enumerated, will operateuniformly, noiselessly, with a practical absence of vibration, and withhigh efficiency... It should furthermore be observed that owing to thelarge area made available for the expulsion of the gas and air, themovement of the floating headsneed only be very slight, say 3 2' of aninch or even less, so that notwithstanding the extreme rapidity of thereciprocations of the pistons, the, floating heads respond with thenecessary rapidity to both the compression and suction impulses setup bythe pistons. 7

' We claim: I

1. .A refrigerating machine comprisin a casing enclosing a high pressureand a ow pressure chamber, the former being super- Imposed upon thelatter, compressors'for the refrigerant located in and having intakescommunicating drectly with the low pressure' chamber, said compressorshaving valvedcommunication with the high pres-. sure chamber, means forconducting evaporated refrigerant into the low pressure chamber,bearings rovided in a wall of the low pressure cham er and an oppositeartitionseparating the two chambers, a rive shaft for operatingsaidcompressors pro jecting from the outside into and through said lowpressure chamber and mounted toward its ends insaid bearings, and meansfor driving said shaft. 2. A refrigeratin machine comprising a casingenclosing a igh pressure and a low pressure chamber, means forconducting evaporated refrigerant into said low ressure chamber, comressors for the refrigerant located in an havin intakes commu nicatingdirectly with t e low pressure chamber, said compressors having valvedcommunication with the high pressure chambers, a drive shaft enteringsaid low pressure chamber through its bottom for operating saidcompressors, means for driving said shaft, and a combined bearing andstufling box provided for said shaft on the bottom of the low pressurechamber, the stufling box being accessible to a lubricant maintained inthe bottom portion of said low pressure chamber.

3. A refrigerating machine comprising a casing enclosing a high pressureand a low pressurechamber, means for conducting evaporated refrigerantinto said low pressure chamber, compressors for the refrigerant locatedin and having intakes com- .municating with the low pressure chamber,

, said compressors having valved communication with the high pressurechambers, a drive shaft projecting through the bottom of said lowpressure chamber into the same for actuatin said compressors, a bearingfor said she t provided on the bottom and projecting into the interiorof the low pres sure chamber, and a stufiingbox for the shaft locatedexteriorly of the chamber, said bearing being provided with aperturesfor permitting access to said s u ng box of lubricant maintained in thelower part of said low pressure chamber.

4. A refrigerating machine comprising a casing enclosing a high pressureand a low pressure chamber, each of which chambers contains a body oflubricant, means forconducting evaporated refrigerant into the lowpressure chamber, compressors for the refrigerant located in and havingintakes communicating with the low pressure chamber, said compressorshaving valved communication with the high pressure chambers, a driveshaft for actuating thegcompressors havingbearings in correspondingwalls of said chamber, the wall of the high pressure chamber affording apassage for lubricant from said chamber to the low pressure chamber tolubricate the compressing mechanism therein, and means for controllingthe flow of lubricant from the high pressure chamber through saidpassage.

5. A refri erating'machine comprising a casing enclosing a high pressureand a low pressure chamber, each of which chambers contains a body oflubricant, means for conducting evaporated refrigerant into the lowpressure chamber, compressors for the re-v frigerant located in andhaving intakes communicating with the low pressure chamher, said comressors having valved communication with the high pressure chambers, adrive shaft for actuating the. compressors projecting throughcorresponding walls of said chambers, the wall of thehi h ressurechamber affording a assage or ubricant'from said chamber to t e lowpressure chamber to lubricate the compressing contains a body for therefrigerant located in the low pressure chamber, a drive shaft foractuating the mechanism therein, and means rated by the drive shaft forcontrolling t e flow of lubricant from the high pressure chamber throughsaid passage.

6. A refrigerating machine comprising a casing enclosing a high pressureand a low pressure chamber, each of which chambers of lubricant,compressors compressors projecting through corresponding walls of saidchambers, the wall of the high pressure chamber affording a passage forl ricant from said chamber to the low pressure chamber to lubricate thecompressmg mechanism therein, and means located in the high pressurechamber and operated by the drive shaft to control the flow of lubricantfrom said chamber through said passage.

' 7. A refrigerating machine comprising a casing enclosing a highpressure and a low pressure chamber, each of which chambers contains abody of lubricant, means for conducting evaporated refrigerant into thelow pressure chamber, compressors for the refrigerant located in andhaving intakes communicating with the low pressure chamber, saidcompressors having valved communication with the high pressure chambers,

a drive shaft for actuating the compressors having bearings incorrespondin walls of said chambers, the wall of the big pressurechamber affording a passage for lubricant from said chamber to the lowpressure chamber, means in the latter chamber for distributing lubricantfrom said passage to the compressing mechanism, and means forcontrolling the flow of lubricant from the high pressure chamber throughsaid passage.

8. A refrigerating machine comprisin a casing enclosing a high pressureand a ow pressure chamber, each of which chambers contains a body oflubricant, means for con- ,5

ducting evaporated refrigerant into the low pressure chamber,compressors for the refrigerant located in and having intakescommunicating directly with the low pressure chamber, a drive shaft foractuating the compressors having hearings in corresponding walls of saidchambers, the wall of the high ressure chamber aflording a passage forubricant from said chamber to the low latter chamber mounted on thedrive shaft for receiving and distributing lubricant from said passageto the compressing mechanism, and means operated by the drive shaft forcontrolling the flow of lubricant from the high pressure chamber throughsaid passaga' 9. A refri rating machine comprising a casing. enclosing ahigh pressure and a low pressure chamber, each of which chamberscontains a bodyof lubricant, means for conressure chamber, means in theducting-evaporated refrigerant into the low ressure chamber, compressorsfor the reigerant located in and having intakes communicating directlywith the low pressure chamber, said compressors having valvedcommunication with the high pressure chamber, a drive shaft foractuating the compres- .sors of said chambers, the wall of the bigpressure chamber affording a passa e for lubri cant from said chamber tothe ow pressure chamber, means in the latter chamber for distributinglubricant from said passage to the compressing mechanism, and meanslocated in the high pressure chamber and op-,

erated by the drive shaft to control the flow oflubricant from saidchamber through said Passage- .7 4

10., A refngeratmg .machme comprising a casing enclosing a high pressureand a lowpressure chamber,- each of which chambers contains a body oflubricant,

projecting through correspondin walls ricant from said chamber bricantfrom said chamber through said passage, and means including thecompressors forireturning the lubricant from the low chamber to the highpressure cham- ,11. A refrigerating machine comprising a casingenclosing a high pressure and a low pressure. chamber, each of-whichchambers contains a body of lubricant, means for con ducting evaporatedrefrigerant into the low pressure chamber, compressors for therefrigerant located in and having intakes com municating directly withthe low pressure chamber, said compressors having valved communicationwith the high pressure chamber, a drive shaft for actuating thecompressors projecting through corresponding wallsof said chambers, thewall of the high pressure chamber affording communication for lubricantfrom said chamber to the low pressure chamber to lubricate saidcompresslng mechanism, and means operated by the drive shaft toalternately open and close the communication between the two chambers tocontrol the flow of. lubricant under pressure in thehigh pressurechamber through said passage.

12. A refrigerating machine comprising a 1 ,s m'ro casing enclosing ahigh pressureyaiid a low pressure chamber, each of which chamberscontains a body of lubricant, means for-con-' ducting evaporatedrefrigerant into the low pressure chamber, compressors'for.tl1erfrigerant located in and having intakes com-,

municating directly with the low pressure chamber, said compressors.having valved and a plurality of means, including the-compressors,actuated in the operation of the machine to controllably supplylubricant from the high pressure chamber to the low pressure chamber, todistribute the lubricant to the compressing mechanism in the latterchamber, and to-return-surplus lubricant from the low pressure to thehigh pressure chamber. p

13. A refrigerating machine comprising a casing enclosing a highpressure and a low pressure chamber, each of which chambers contains abody of lubricant, means for'conducting evaporated refrigerant into thelow pressure chamber, compressors for the refrigerant located in-andhaving intakes communicating directlysvith the low pressure chamber,said compressors having valved communication with the highpressure'chamber, a drive shaft projecting through corresponding wallsof said chambers, the wall of the high pressure chamber affording apassage for lubricant from said chamber to the low pressure chamber,means mounted on the drive shaft for operating said compres. sors, meanscarried by the shaft-for receiving and distributing the oil to thecompressing mechanism, means operatedby the drive .shaft for controllingthe flow of lubricant from the high pressure chamber through saidpassage under the pressure of the lubri cant in the high pressurechamber, and

means, including the compressing mechanism, for returning surplus;-lubricant from the low pressure to the highpressiim chamber, whereby tomaintain a substantially con stant oil level in said chambers.

14. A refrigerating machine comprising a casing enclosing a highpressureand a low pressure chamber, each of whrchchambers contains abody of lubricant, means for conducting evaporated refrigerant into thelow pressure chamber, compressors for the refrigerant. located in andhaving intakes communicating directly with the lowpressure chamber, saidcompressors having valved.-

. communication with the high pressure chamber, a drive shaft projectingthrouglrgcorresponding walls of said chamber, .means mounted on thedrive shaft for operating said compressorasaid means being. providedwith ducts for the flow of lubricant and the wall of the high'pressurechamber affording a passage for lubricant from said chamber to tweeneach of said chambers: andthe hi h the shaft for receiving anddistributing the oil to said ducts, means for controlling theflowbf-lubricant from the high pressure chamber through said passageunder the pressure of the lubricant in the high preslubriantwfrom thelow pressure tothe. high pressure chainberfwvhereby to, maintain asubstantially constant oil le'vel in said chambers.

surechamber, and means,'including the compressing mechanism,for'returnmg surplus I .15. A refrigeratin machine comprising acasm'ge'nclosing a hlgh' pressure and a low pressure, chamber, I meansfor conducting evaporated refrigerant into the low pressure chamber, comressors for the refrigerantvlocated in and l aving intakes communicatingdirectly with the low pressure chamber, each of which compressorscomprises in turna cylinder provided with an exterior head 'affordinga'chamber h'aving'valved communication with the cylinder, pipesafi'ordiiig communication between each of said chambers and the highpressure chamber, a'piston in each of said cylinders, a drive shaftextending into the low pressure chamber at right angles to the axes ofsaid cylinders, means on said drive shaftfor actuating said plistfcins,and means for actuating the drive s a 16.- A refrigerating machinecomprising a casing enclosing a high pressure and a low pressurechamber, means for conducting evaporated refrigerant into the-lowpressure chamber, compressors for the refrigerant located at oppositesides of and havin'g in takes communicating directly with the low withan exterior head affprding a chamber 7, jhavirag valved c0mmun1c11t;igxwith the cylin pipes affording comiiiunication beprcssure chamberg apistop each of said cylinders, av drive *"shaft'siittanding into the lowpressure chamber at right angles to the need said cylinders, means-onsaid drive shaft for actuating said pistons, and means for actuating thedrive shaft.

-17. Arefrigerating machine comprising a v casing enclosing a highpressure and a low pressure chamber, each of which chambers contains abody of lubricant, means for conducting evaporated-refrigerant into thelow pressure chamber, compressors for the refrigerant located in the lowpressure chamber, and having valved communication with the high pressurechamber, means for actuating said compressors, a condenser for the compressed refrigerant in the high pressure chamber, the wall of the highressure chamber affording'a passage for ubricant from said chamber tothe low pressure chamber to the low pressure chamber, means carried bylubricate the compressing mechanism in the contains a body of lubricant,means for con ducting evaporated refrigerant into the low pressurechamber, compressors for the refrlg- 'erant located in the low pressurechamber,

and having valved communication with the high pressure chamber, meansfor actuating said compressors, a condenser for the refriggerant locatedin the high pressure chamber, whereby a body of condensedrefrigerantwill be constantly superimposed upon the body of lubricant in the highpressure chamber, means for withdrawing condensed refrigerant from above-the level of the lubricant in the high pressurechamber, means forsimultaneously withdrawing lubricant from below the level of thelubricant in the bottom of the high pressure chamber for lubricating thecompressing mechanism in the low pressure chamber, and means forreturning excess lubricant from the low pressure-tothe high pressurechamber. 7

19. A refrigerating machine comprising a casing enclosing a highpressure and a low ressure chamber, the former being superimposed uponthe latter and each of said chambers containing a body of lubricant,

' means for conducting evaporated refrigerant into the low ressurechamber, a bearing provided in the ottom of each of said chambers andsurrounded and lubricated by the lubricant thereof, com ressors for therefrigerant located in and having intakescommunicating directly withsaid low pressure chamber, said compressors having valved communicationwith the high pressure chamber, and a drive shaft for actuating saidcompressors extending through said low pressure chamber and mounted nearits opposite ends in the said bearings.

20 A refrigerating machine .comprising a casing enclosing a highpressure anda low pressure chamber, each of which chambers contains abody of lubricant, means for conducting evaporated refrigerant into thelow pressure chamber, compressors for the refrigerant located in andhaving intakes communicating directly with the low pressure chamber.said compressors having valved communication with the high pressurechamber, a drive shaft for actuating the compressors projecting throughcorresponding walls of said chambers, the wall of the high pressurechamber affording a passage for lubricant from said chamber to the lowpressure chamber, means mounted on the drive shaft for actuating thecompressors, said means being located beneath the discharge end of saidpassage for receiving lubricant therefrom and provided with means forconveying the lubricant to-the moving parts of the actuating andcompressing mechanism, whereby the lubricant while flowing from the highto the low pressure chamber will be caused to lubricate all of saidmoving arts, and means 'forautomatically controlling the discharge oflubricant from the high pressure chamber through said passage under,the. pressure in said chamber.

21. A refrigerating machine comprising a casing enclosing a highpressure and (a low pressure chamber,means for conducting evaporatedrefrigerant into the low pressure chamber, compressor cylinders fortherefrigerant located at diametrically opposite sides of and within thelow pressure phamher; and each of which cylinders is provided with apiston, a driveshaft extending into the low pressure chamber at rightangles to the axes of said cylinders, means on said shaft for actuatingsaid pistons synchronously, alternately in opposite directions, inletports in said cylinders in free communication with the low pressurechamber, floating heads on the compression ends of the cylinders movableunder pressure to uncover the entire area of the cylinders, and meansfor conducting gas expelled from the cylinders to the high pressurechamber.

' 22. A refrigerating machine comprising a casing enclosing a highpressure and a low pressure chamber, the latter containing a body oflubricant, means for conducting evaporated refrigerant into the lowpressure chamber, compressors for the refrigerant located in and havingintakes communicating directly with the low pressure chamber, saidcompressors having valvedcommunication with the high pressure chamber,means for actuating the compressors. pipes communicating with saidcompressors and having a common connection provided with an.

opening located adjacent the surface of said bodv of lubricant. whereby,in the operation of the compressors. lubricant will be simultaneouslvdrawn into each compressor. and floating heads on each c'ylinder adaptedto yield under the compressive actionof the pistons to permit the freedischarge of oil from the cylinders.

23; A refrigeratinr machine comprising a casing enclosing a hi hpressure and a low pressure chamber. the latter; of which contains abodv of lubricant. means for conducting evaporated refrigerant into thelow pressure chamber. compressors for the refrigerant located 'in. thelow premure chamber. each of said compressors including cylindersprovided with inlet ports freelv communicating with the interior of saidlow pressure chamher, said compressors having valved communication withthe high pressure chamber, means for actuating the compressors, pipescommunicating with the interior of said cyl-' inders in advance of saidinlet ports and having a common inlet located near the surface of saidbodv of lubricant, and a floating head on each of said cylinders adaptedto yield under the compressive action of the pistons to permit the freedischarge of the lubricant from the cylinders.

24. A refrigerating machine comprising a casing enclosing a hlghpressure and a low pressure chamber, each of which chambers contains abody of lubricant, means for conducting evaporated refrigerant into thelow pressure chamber, compressors for. the refrigerant located in andhaving intakes communicating directly with the low pressure chamber,said compressors having valved communication with the high pressurechamher, a. drive shaft for actuating the compressors having bearings incorresponding Walls of said chambers, the wall of the high pressurechamber affording a passage for lubricant from said chamber to the lowpressure ,chamber,-means for controlling the flow of lubricant throughsaid passage, pipes communicating with said-compressors and having acommon inlet located near the surface of the body of lubricant in thelow pressure chamber, floating heads for each cylinder adapted to yieldunder compressive action, whereby, in the operation of the compressorslubricant will be simultaneously drawn into each compressor and freelvdischarged therefrom, and means for conducting the lubricant dischargedfrom the compressors to the high pressure chamber.

In testimony whereof, We have hereunto set our hands.

JOHN E. MITCHELL. WALTER G. E. RULAFF.

